(1) Field
The disclosed methods and systems relate generally to annealing processes, and more particularly to athermal annealing.
(2) Description of Relevant Art
Conventional ion implantation systems include ionizing a dopant material such as boron, accelerating the ions to form an ion beam having a given energy level, and directing the ion beam energy at a semiconductor surface or wafer to introduce the dopant material to the semiconductor and alter the conductivity properties of the semiconductor. Once the ions are embedded into the crystalline lattice of the semiconductor, the ions can be activated using a process known as rapid thermal annealing (RTA) or rapid thermal process (RTP). During RTA, the semiconductor can be introduced to a furnace to heat the semiconductor at a prescribed temperature and for a prescribed time. RTA can also cure defects in the crystalline structure that can be caused by the ion implantation.
The processes of ion implantation and RTP contribute to the depth of the implanted region, known as the junction depth. Those of ordinary skill in the art recognize that the junction depth from ion implantation is based on the energy of the ions implanted into the semiconductor. Accordingly, shallow implanted regions can be formed using low-energy ion beams. Unfortunately, traditional methods of RTA include raising the temperature of the silicon to ranges nearing 1100–1200 degrees Celsius, which can approach the melting temperature of the silicon. Accordingly, RTA can further increase the implanted junction depth as high temperatures of the RTA process cause further diffusion of the implanted region.
The increase in junction depth can be particularly troublesome when considered with respect to a continuing and expanding demand for smaller devices, and hence shallower junction depths. It is anticipated that the present methods and systems that combine ion implantation solely with traditional RTA may not satisfy the demand for shallower junctions.